e7
1/18/2019 - 7:07 AM

determin buffer-length of snprintf

确定格式化字符串所需缓冲区大小

buffer-len.c
content_copyfile_download
int bufferSize(const char* format, ...) {
    va_list args;
    va_start(args, format);
    int result = vsnprintf(NULL, 0, format, args);
    va_end(args);
    return result + 1; // safe byte for \0
}